How to get Instagram real followers more often without PPC

Hello,

I have been using IG for long now, mostly I post 2/3 updates on my business profile every day. I do hashtags trend research once in a week for the following posts. Mostly I get 20-25 likes from them, but very fewer followers such as 2/3 max. Now someone advises me to go for PPC, but my budget isn't following that for now. Are there any tips on improving my followers?